Dry-placer-mining machine



Feb- 11,1930. l. c. LIGHTFoo'r I 1,746,706

DRY PLACER MINING MACHINE Filed July 26. 192e 2 sheets-sneer 2 Patented Feb. y11, 1930 UNITED STATES PATENT oFFlcE ISAAC CARLETON L-IGrI-ITFOOT, OF MERRIAM, KANSAS DRY-PLACEB-MINING MACHINE Application filed July 26,

This inventionrelates to improvements in dry placer mining machines of the typeA em ployed in arid regions for separating gold and other valuable metals from nonmetalliferous sands and gangue.

This invention is an improvement over the invention shown and described in U. S. ap?` plication Serial No. 239,432, filed December 12, 1927, of which I am a joint inventor.

It is the object of this invention topro duce a machineof simple construction that can be readily transported to the pla-ce where it is to be used and which shall be adapted to separate the gold from auriferous sands without the use of water.

In this and many other countries gold occurs mixed with sand and other nonmetal` liferous gangue in regions where water is very scarce. It has'heretofore been impractical to recover this gold, owing to the absence of water, and therefore these potentially rich deposits have been left untouched.

\ It is apparentthat ifa successful machine can be producedloy means of which the gold can be separated from these sands without the use of water, it will become possible to recover gold from these deposits.

The present invention relates to an improved machine of the type above referred to, which will now be described in detail, reference for this purpose being had to the accompanying drawings, in which the preferred embodiment thereof has been illustrated, and

`in which:

Fig. 1 is a side elevation of my improved machine portions thereof being broken away to better disclose the construction;

Fig. 2 is a section taken on line 2--2, Fig. 1, and shows a detail of the construction;

Fig. 3 is a section taken online 3--3, Fig. 1, and shows the nozzle by means of which a blast of air is introduced into the rotating cylinder; Y

Fig. 4 is an end elevation ofthe crusher,

' partly broken away looking in the direction of arrow 4, Fig. 1';

Fig. 5 is a section taken on line 5 5, Fig. 1; Fig. 6 is a section taken on line 6-6, Fig. 1, and

Fig.

7 is a section taken on line 7-7, Fig. 6.

1928. Serial No. 295,442.

Numeral lrepresents one of the side members of a frame on which the rotatingcylinder 2 is supported. 4This frame is provided with supporting legs 3 at each of its four corners. Secured to, each of the side members 1, are bracket-s 4, each carryingtwo rollers 5. These brackets are preferably secured to the side members by means o f bolts or rivets 6. Secured to one end of the cylinder 2 is a conical member 7 whose larger end is inserted intothe end of cylinder 2 and is spaced from the latter by means of channel or I-beam sections 8, which serve to hold the two parts in concentric relation so as to provide an annular space 9 between the outer surface ofthe conical member and the inner surface of the cylinder. Secured to the smaller end of the conical member 7 is a gear wheel 10 whose hub 11 is fastened to the end portion of conical member 7 by means 70" of rivet-s. This gear has formed integral therewith, a cylindrical member provided with a groove 12, which is adapted to receive the rollers 5 for the purpose of supporting the front end of the assembly. A ring 13 encircles the cylinder 2 and has its outer surface provided with a groove for the reception of the rollers 5. `When the assembly comprising the cylinder 2 and conical member 7 is mounted on the rollers inthe manner 30 shown in Figs. 1 and 5, it may be rotated about the axis of the cylinder in a manner quite apparent. Forthe purpose of rotating the assembly, I have provided shaft 14 which is journalled in bearings 15 and 16 and which carries a sprocket gear pinion 17 that meshes Y with the teeth of gear lO and a beveled gear 18 that meshes with another beveled gear 19, which is secured to a shaft 2O that is rotatably mounted in bearings 21. The outer end of shaft 20 carries a pulley 22 to which power is transmitted by means ofa belt 23. It is apparent that when the shaft 20 is rotated, the cylinder 2 will also be rotated. Carried by the supporting frame is a rotary fan which has been indicated by reference numeral 24. This fan is provided with a pulley 25 to which power is transmitted by means of a belt 26. The outlet port 27 has connected to it a nozzle 28 which'embraces the inner end 100 of the conical member 7 and extends about one hundred eighty degrees about the lower surface of the latter'. This nozzle opens into the annular space 9, and when the fan is rotated, it directs a blast of air into the cylinder 2. The inner surface of cylinder 2 is provided with a plurality of ribs 29 that have been shown as formed from angle irons riveted to the inner surface of the cylinder. These ribs may, however, be formed in any other way as they are intended merely to carry the powdered material upwardly when the cylinder is rotated. and to permit the same to fall downwardly through the cylinder so as to be caught by the airblast and carried towards the discharge end of the cylinder.

Located at the discharge end of the cylinder is a hollow member formed from sheet metal and which has been indicated as a whole by numeral 30. This member has a cross section substantially like that shown in Fig. 6 from which it will be seen that the upper surface is substantially horizontal and is connected to the vertical sides 3l and 32 by means of curved portions 33. The vertical sides extend parallel down to point 34 and are then inclined inwardly so as to form two inclined sides 35 that terminate at a point 36. The inclined sides 35 are preferably lined by a sheet of metal 37 which is grooved longitudinally in the manner indicated in Fig. 6. The entire inner surface of the hollow member 3() is preferably amalgamated, so that any free gold that comes in contact with the surface will adhere to it. The curved corners 33 facilitate the cleaning of the inner surfac and are therefore used instead of square corners which would make it more diicult to clean up after a run has been made. Se-

. cured in the outer end of the hollow member 30, are two frames 38 and 89. These frames are shaped so that they will fit the interior of the hollow member and are provided with straight lower sides 40 that rest on the sup porting brackets 41. Each frame is provided with a plurality of plates 42 that are parallel but inclined and overlap each other in the manner shown in Fig. 7. The inner surfaces of these plates are amalgamated or covered with a film of mercury for the purpose of catching any free gold or other metal that ma come in contact with them. As it is desirable to clean the amalgamated surfaces from time to time, the frames havebeen so connected to the member 30 that they can be readily removed and are held in place by means of pins 43 which serve to prevent them from being blown out during the operation of the apparatus. Member 30 is supported by two separate frames each of which comprises two substantially vertical supporting members 44 and 45 whose ends are connected by means of an angle iron 46. The supports 44 and 45 are also connected by means of a bar 47 and are provided with a plurality of gusset stays 48, which keep the members in proper relation. The vertical sides 3l and 82 are each provided with a Z-bar 49, one flange of which extends downwardly and is adapted to overlap the upwardly extending flange of the angle iron 46. The frames are held against spreading by means of braces 50 that are attached to the sides 35 by means of a pivot 51 and are provided with notches that engage pins 52 in the vertical support. The hollow member 30 is located adjacent the delivery end of cylinder 2 and the latter preferably extends a short distance into the interior of member 30 in the manner shown in Fig. l.

Located adjacent the small end of the conical member 7 is a crusher which comprises a pair of steel rollers 53 that are each provided with axial extensions or shafts 54 that are rotatably mounted in suitable bearings carried by a supporting frame which comprises upwardly extending supports 55. A hopper 56 encloses the rollers and is constructed so that the inclined walls 57 direct the material into the space between the rollers which rotate in the direction indicated by the arrows in Fig. l. Each shaft is provided with two gear wheels 58 that intermesh and which have a pitch diameter equal to the diameter of the rollers. One of the shafts is provided with two pulleys 59 to which power is transmitted by means of belts 60. A shaft- 61 is ournalled in bearings 62 carried by the horizontal frame member 63. This shaft is provided with a pulley 64 to which power is transmitted from a prime mover, not shown, by means of a belt 65. Shaft 61 is also pro vided with two pulleys 66 which cooperate with the belts 60, for the purpose of rotating the rollers. The pulley 67 cooperates with the belt 23 for the purpose of rotating shaft 20 and a pulley 68 cooperates with the belt 26 for the purpose of rotating the fan. The conveyor comprising a chain 69 having buckets 70 has been indicated in Fig. l and serves to elevate the sand and other material into the hopper 56.

Let us now assume that the parts have been assembled in the manner shown in Fig. l, and. that sand containing gold particles is to be treated. This sand is elevated into the hopper by means of the conveyor and will pass downwardly between the rollers. The

rollers are so adjusted that they will crush.

the sand to the desired fineness. From the rollers the sand passes through the chute 7l, into the end of the conical member 7 and passes from thence into the cylinder 2. When the parts are in operation the fan will, of course, be rotated at the required speed and will produce a blast of air which enters the cylinder through the nozzle'28. Vhen the crushed sand and gold pass from the conical member 7, they fall into the stream of air and are carried along towards the delivery end of the cylinder, and are then blown into the hollow member 30 and against the amalgamated surfaces of the plates 42. Any gold particles present will adhere to the amalgamated surfaces. Of course some of the sand willfall onto the lower surface of cylinder 2 and will be carried upwardly by the ribs 29 and will then be dropped downwardly so as to again enter the air stream. In this way the sand and gold is repeatedly subjected to the action of the airblast which tends to move the heavier material towards the open end and which entrains the lighter material and gold particles and throws them with great force against the amalgamated surface, where theV gold remains owing to the great aflinity between the gold and the mercury, while the nonmetallic particles fall to the bottom and escape through the opening 72.

I want to call attention to the fact that this machine is so constructed that it can be readily separated into several parts so as to facilitate transportation.

At this point I desire to call attention to the fact that the amalgamation chamber has been provided with a deiiector plate 75, whose upper surface is provided with an edge 76. This plate is symmetrical with respect to a vertical plane passing through the center of the amalgamation chamber and its inclined sides serve to defiect the material towards the amalgamated inner surfaces of the chamber and to spread the materials blown against it by the air chamber.

Since the walls of chamber 30, as well as the surfaces of plates 42 and the surface of plate 75 are covered with mercury, it is essential that these parts be as free as possible from vibration as vibration will cause the mercury to flow. The amalgamation chamberis therefore entirely separated from the other parts of the machine so as to prevent vibrations from beingtransmitted to it from the other parts.

Having described my invention what is claimed as new is:

l. A dry placer mining machine comprising, in combination, a cylinder having its inner surface provided with inwardly extending ribs, means for rotating ther cylinder, means f-or directing a blast of air into one end of the cylinder, means for feeding dry powdered ore into the cylinder adjacent the place where the air enters, a tubular member located at the delivery end of the cylinder and embracing the latter, and two rows of plates extending across the open end of the tubular member, the plates in one row being staggered with respect to the plates in the other row and have the surfaces facing the cylinder covered with mercury.

2. A dry placer mining machine for use in separating metallic values from nonmetallic gangue comprising a cylinder having its inner surface provided with a plurality of ribs,

means for supporting the cylinder so that it may be rotated about its axis, means for rotating the cylinder, a hollow conical member having its large end located within one end of the cylinder, means for securing'the conical member to the cylinder, the outer surface of the conical member being of smaller diameter than the inner surface of the cylinder whereby an annular space is provided between the two, means for directing a blast of air into the cylinder through the annular space, means for introducing powdered ore into the conical member whereby it will be conveyed to the cylinder and into the air stream and an amalgamating chamber located at the delivery end of the cylinder so as to receive the material carried by the air stream, the inner surfaces of said chamber being amalgamated.

3. A dry placer mining machine for use in separating metallic values from nonmetallic gangue comprising a cylinder having its inner surface provided with a plurality of ribs, means for supporting the cylinder so that it may be rotated about its axis, means for rotating the cylinder, a hollow conical member having its large end located within one end of the cylinder, means for securing the conical member to the cylinder, the outer surface of the conical member being of smaller diameter than the inner surface of the cylinder whereby an annular space is provided between the two,`means for directing a blast of air into the cylinder through the annular space, means for introducing powdered ore into the conical member whereby it will be conveyed to the cylinder and into the air stream, an amalgamating chamberl located at the delivery end of the cylinder so as to receive the material carried by the air stream, the inner surfaces of said chamber being amalgamated and a plurality of removable frames within the chamber, each frame having a plurality of plates extending transversely thereof, said plates having the surface on one side amalgamated.

In testimony whereof I affix my signature.

ISAAC GARLETUN LIGHTFQOT.

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